The present invention relates to a wireless communication device that performs transmission and reception in a time-division manner. Specifically, the present invention relates to a wireless communication device that has a function of self-diagnosing a transmission system and a reception system.
A wireless communication device that performs transmission and reception in a time-division manner generally includes a transmission system circuit that performs modulation, amplification and the like of a transmission signal; a reception system circuit that performs amplification, demodulation and the like of a reception signal; and a transmission/reception switchover switch that switches between a transmission period and a reception period by connecting either of these two types of circuits to an antenna.
In an example of the wireless communication device disclosed in Japanese Unexamined Patent Application Publication No. 5-145499, a loopback path is formed, which is designed to input the transmission signal from the transmission system circuit directly into the reception system circuit, between a transmission signal path leading from the transmission system circuit down to the transmission/reception switchover switch and a reception signal path leading from the transmission/reception switchover switch down to the reception system circuit. The example is configured to perform a fault diagnosis of the transmission system circuit and the reception system circuit by determining whether or not the transmission signal from the transmission system circuit has been successfully received by the reception system circuit.